1. Identify the reactants and products: Reactants are CaCO₃ (calcium carbonate) and HCl (hydrochloric acid). Products are CaCl₂ (calcium chloride), H₂O (water), and CO₂ (carbon dioxide).
2. Write the unbalanced chemical equation: CaCO₃ + HCl → CaCl₂ + H₂O + CO₂
3. Balance the equation by adjusting coefficients:
- Calcium (Ca): 1 on left, 1 on right → balanced.
- Carbon (C): 1 on left, 1 on right → balanced.
- Oxygen (O): 3 on left (from CaCO₃), 3 on right (1 from H₂O + 2 from CO₂) → balanced.
- Hydrogen (H): 1 on left (from HCl), 2 on right (from H₂O) → not balanced.
- Chlorine (Cl): 1 on left (from HCl), 2 on right (from CaCl₂) → not balanced.
4. Add a coefficient of 2 in front of HCl to balance H and Cl:
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
5. Verify atom counts:
- Ca: 1 = 1
- C: 1 = 1
- O: 3 = 1 (H₂O) + 2 (CO₂) = 3
- H: 2 (2HCl) = 2 (H₂O)
- Cl: 2 (2HCl) = 2 (CaCl₂)
6. The balanced chemical equation is: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
Parent Tip: Review the logic above to help your child master the concept of endothermic and exothermic worksheet.
